Cold, hard and thin: General Industry Coverage

With hardness greater than 40 Gpa, diamond-like coatings (DLCs) provide a low coefficient of friction, resist chemical attack and protect against abrasive wear for a host of applications, such as cutting tools and wear components in machine tools.

Conventional pulsed-laser deposition (PLD) takes place in a vacuum chamber and deposits thin films of coatings, such as DLCs, but it’s difficult to deposit uniform coatings and form the required particle-free coatings, according to Picodeon Ltd. Oy, a coating equipment manufacturer. These challenges limit the scalability of the process to industrial production.

Courtesy of Picodeon

A cutting tool insert with a diamond-like coating deposited via Picodeon’s Coldab US PLD process.

To achieve the desired composition, the company reported that it developed the ultrashort PLD cold-ablation process based on a high-power laser beam with a pulse duration typically less than 10 picoseconds. (A picosecond is one trillionth—0.000000000001—of a second.) This enables coating substrates at temperatures below 100° to 150° C. In addition, a cold-ablation method’s plasma does not contain a significant proportion of molten material and particles, which are found in hot-ablation processes that use lasers with pulse lengths in the nanosecond regime.

Called Coldab, the US PLD technology is suitable for depositing DLCs and other coatings with thicknesses from a few hundred nanometers to 2µm to 3µm on virtually any substrate, including metals, ceramics, composites, elastomers and even tissue paper.